It is desirable to perform asymmetric halo implants to increase device performance. When there are various intellectual property (IP) blocks, such as SRAM components or a microprocessor core, verification of the correct orientation of the IP blocks may be needed so that the asymmetric halo implants, if present, will be performed in the correct direction or orientation on the correct location in each IP block. Typically, this verification occurs by checking each step in the design data flow between the data design and mask design. This is a slow and difficult process, which increases cycle time. In addition, there currently is no ability to verify the orientation in the manufacturing process.
Existing structures have appeared on masks and integrated circuits, such as alignment keys (which may be the shape of a Christmas tree or cactus) and critical dimension (CD) bars. But these existing structures are used for dimensional and overlay control.
Therefore, a need exists to verify orientation in the manufacturing process. In addition, it is desirable to improve cycle time when verifying correct orientation of IP blocks.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve the understanding of the embodiments of the present invention.